An idle mode is a terminal working mode in mobile broadband wireless access system defined by IEEE 802.16e standard. In the idle mode, the terminal may move in a given area and receive downlink broadcast service messages every a certain period, through which the terminal is informed by the system whether there is a downlink service to be sent. The terminal does not have to register with a base station of this cell when roaming in this area. At the same time, no operation flow, such as switching, need to be performed when the terminal roams to a different cell, thereby facilitating saving power and air interface resources of the terminal.
In this scheme, a plurality of base stations constitute a paging group, so as to form a consecutive area, in which the terminal does not necessarily send an uplink service, but may determine whether there is any downlink service to be sent to it at the network side through a downlink paging path. The paging group should be large enough to ensure that most of the terminals remain in the range of the same paging group for a long time, thus avoiding a frequent location updating. Also, the paging group should be small enough to ensure that the cost for paging the terminals in a paging group is reasonable.
In a normal connection mode with a certain serving base station, the terminal may request to enter the idle mode by sending a message, and the serving base station may also actively require the terminal to enter the idle mode by sending a message.
The currently formulated worldwide interoperability for microwave access (WiMAX) standard defines a paging reference model in the idle mode, as shown in FIG. 1. FIG. 1 is a schematic structural view of a WiMAX paging network. It can be seen from the figure that, a paging controller is a network entity that controls the idle mode activity of the terminal, which is a logical entity in the current WiMAX network architecture and has a close relationship with another logical entity, namely, authenticator (it may be realized in the same physical network element with the authenticator). The paging controller may be located in a physical network element of the WiMAX network, namely, access service network gateway (ASN-GW), and may also be located in another independent physical network element. Furthermore, the paging controller needs to initiate a paging process according to the paging group in which the terminal is currently located, and thus a location register is required to store state information of the terminal, paging information, and service flow related information. In general, a logical entity of the paging controller is corresponding to a logical entity of the location register, and both logical entities are realized in the same physical network element.
In the WiMAX network architecture, the authenticator, the paging controller, and the location register currently mentioned are a logical function entity, and belong to a functional portion of the ASN-GW. In the current paging solution, it deems that when the terminal is in the idle mode, the authenticator and the paging controller do not change, and it deems that after the terminal enters the idle mode, an anchor authenticator that stores the terminal key information and an anchor paging controller do not change, although physically, in the idle mode, the terminal may move to the physical dominion of another paging controller and authenticator. If the paging controller and the authenticator are realized on the same physical entity, when the terminal enters the idle mode or leaves the idle mode, or performs a location updating, the terminal can store or obtain a message to or from both the paging controller and the authenticator as long as interacting with the physical entity, thereby accomplishing the related management of the terminal in the idle mode.
When the mode of the terminal changes or a network switching is performed, various function entities corresponding to the terminal, which currently serve the terminal, become anchor entities, such as an anchor authenticator, an anchor paging controller, an anchor data path function, an anchor foreign agent, an anchor service flow authorization (anchor SFA) entity, a dynamic host configuration protocol proxy (DHCP proxy) entity, an anchor accounting client, and the like.
For the above function entities, by the movement of the terminal, since the moments of the function entities serving each terminal MS trigger a change respectively are different, the above various function entities serving a particular terminal MS, such as the anchor authenticator, the foreign agent FA, the anchor SFA, the anchor proxy mobile IP client (anchor PMIP client), and the like, may exist in different ASN-GWs, and therefore, interactions between different ASN-GWs would be involved in one activity.
It should be noted that, the above function entities exist within each access service network (ASN). When a subscriber terminal MS accesses the network, the function entities serving the subscriber terminal MS exist in the serving ASN, and the function entities may migrate along with the movement of the MS, the optimization of the network resources, and other reasons. It should be noted that, the migration herein refers to the migration of the function entities serving the MS, i.e., the migration of the anchor function entities of the MS mentioned in the present invention rather than the function entities themselves. That is to say, although each ASN has same function entities, it may not provide services for the MS at this time. The migration may result in various function entities serving the MS being distributed in a plurality of ASNs.
Thus, in the rang of a network access provider, after the terminal enters the idle mode, as the terminal moves, even if the aforementioned anchor paging controller, anchor authenticator, anchor foreign agent, anchor data path function, anchor proxy mobile node, and other logical function entities are realized in the same physical entity, due to different trigger factors and moments for changing the above function entities during the movement, the terminal would be under a particular base station in the idle mode because of the movement. Physically, the base station is connected with a new authenticator and a new paging controller and foreign agent, but the anchor paging controller, anchor authenticator, anchor foreign agent, anchor data path function, and anchor proxy mobile node are not in the same network physical entity.
As shown in FIG. 1, a schematic structural view of a WiMAX paging network without considering other physical network elements and logical entities in the WiMAX network is shown. The ASN-GW 300 is a current ASN-GW of the terminal, the ASN-GW 500 is an anchor foreign agent of the terminal, and the ASN-GW 400 is the ASN-GW in which an anchor paging controller and an anchor authenticator of the terminal are located.
The information should be sent to the anchor paging controller when the terminal enters the idle mode, and the anchor paging controller then finds an associated location register to store the information, so that when the terminal experiences a location updating under some base station in the idle mode, or leaves the idle mode, it should know the specific information of the anchor paging controller, the anchor authenticator, the anchor data path function, and the anchor foreign agent serving the terminal, so as to accomplish functions in corresponding entities. For example, when performing the location updating, the key information should be obtained from the anchor authenticator, for validating legality of the current location updating message; when leaving the idle mode, a corresponding session message, including the information of the anchor foreign agent, the anchor data path function, and the anchor proxy mobile node, should be obtained from the anchor paging controller/location register, thereby establishing a data path corresponding to the terminal. However, the prior art cannot ensure that the above information may be acquired accurately when the terminal enters or leaves the idle mode.
The aforementioned anchor data path function is typically located in the same physical entity with the anchor foreign agent, and sometimes, the concepts of the two logical entities are not mentioned individually, but only the concept of the anchor foreign agent or the anchor data path function is mentioned.